(RFC 5188 published February 2008, subtype last updated February 2008)
Type name: audio
Subtype name: EVRCWB0
Required parameters: None
Optional parameters:
These parameters apply to RTP transfer only.
mode-set-recv: A subset of EVRC-WB modes. Possible values are a
comma-separated list of modes from the set {0,4,7} (see Table
2.5.1.2-1 in 3GPP2 C.S0014-C). A decoder can use this attribute to
inform an encoder of its preference to operate in a specified subset
of modes. Absence of this parameter signals the mode set {0,4,7}.
sendmode: A mode of the EVRC-WB codec. An encoder can use this to
signal its current mode of operation. Possible values are 0,4,7 (see
Table 2.5.1.2-1 in 3GPP2 C.S0014-C). Absence of this parameter
signals mode 0.
ptime: See RFC 4566.
silencesupp: See Section 6.1 in RFC 4788.
dtxmax: See Section 6.1 in RFC 4788.
dtxmin: See Section 6.1 in RFC 4788.
hangover: See Section 6.1 in RFC 4788.
Encoding considerations:
This media type is framed binary data (see RFC 4288, Section 4.8) and
is defined for transfer of EVRC-WB encoded data via RTP using the
header-free packet format specified in RFC 3558.
Security considerations: See Section 18 of RFC 5188.
Interoperability considerations: None
Published specification:
The EVRC-WB vocoder is specified in 3GPP2 C.S0014-C. The transfer
method with the header-free packet format via RTP is specified in RFC
3558 and RFC 5188.
3GPP2 C.S0050-B, 3GPP2 File Formats for Multimedia Services.
3GPP2 specifications are publicly accessible at http://www.3gpp2.org
Applications that use this media type:
It is expected that many VoIP applications (as well as mobile
applications) will use this type.
Additional information: None
Person & email address to contact for further information:
Harikishan Desineni
Intended usage: COMMON
Restrictions on usage:
This media type depends on RTP framing and hence is only defined for
transfer via RTP [6]; the RTP payload format specified in Section 4.2
of RFC 3558 SHALL be used. This media type SHALL NOT be used for
storage or file transfer using the file format defined in Section 8
of RFC 5188; instead, audio/EVRCWB SHALL be used.
Author:
Harikishan Desineni
Change controller:
IETF Audio/Video Transport working group delegated from the IESG.